public class Example4_9 {
    public static void main(String[] args) {
        SIM simOne = new SIM(13889776509L);
        MobileTelephone mobile = new MobileTelephone();
        mobile.setSim(simOne);
        System.out.println("手机号码："+mobile.lookNumber());
        SIM simTwo = new SIM(15967563567L);
        mobile.setSim(simTwo);
        System.out.println("手机号码："+mobile.lookNumber());
    }
}
